QMimeDatabase: handle glob-deleteall tags

According to the Freedesktop spec[1], a mimetype that has glob-deleteall
overwrites other glob-pattern definitions for a mimetype if it is in a
higher precedence dir, the default order is (from high to low)
~/.local/share/mime, /usr/local/share/mime, /usr/share/mime. Or if the
XDG_DATA_DIRS env var is set, then it takes precedence. The
QMime*ProviderS in m_providers are constructed/stored in that same
order, high to low).

For QMimeXMLProvider, we can just clear the glob patterns associated
with those mimetypes from the lists/maps. For the QMimeBinaryProvider
however, we can't change the binary (mmap'ed) cache file, instead check
mimetype names against the exclusion list before modifying a
QMimeGlobMatchResult.

[1] https://specifications.freedesktop.org/shared-mime-info-spec/latest/ar01s02.html

This test uses XDG_DATA_DIRS so only viable when USE_XDG_DATA_DIRS is
defined.

Fixes: QTBUG-101755
Pick-to: 6.5
Change-Id: Icadbdf1027155296377c5a6ab3be8e41b6668325
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: David Faure <david.faure@kdab.com>

1 files changed, 30 insertions, 1 deletions

diff --git a/tests/auto/corelib/mimetypes/qmimedatabase/tst_qmimedatabase.cpp b/tests/auto/corelib/mimetypes/qmimedatabase/tst_qmimedatabase.cpp
index 6bb3bcb1cf..53bcba1be2 100644
--- a/tests/auto/corelib/mimetypes/qmimedatabase/tst_qmimedatabase.cpp
+++ b/tests/auto/corelib/mimetypes/qmimedatabase/tst_qmimedatabase.cpp
@@ -131,7 +131,9 @@ void tst_QMimeDatabase::initTestCase()
     const QString globalPackageDir = m_globalXdgDir + QStringLiteral("/mime/packages");
     QVERIFY(here.mkpath(globalPackageDir));
 
-    qputenv("XDG_DATA_DIRS", QFile::encodeName(m_globalXdgDir));
+    QString overrideDir = QFINDTESTDATA("mimetypes-override/");
+    QByteArray env = QFile::encodeName(overrideDir) + ':' + QFile::encodeName(m_globalXdgDir);
+    qputenv("XDG_DATA_DIRS", env);
     qDebug() << "\nGlobal XDG_DATA_DIRS: " << m_globalXdgDir;
 
     const QString freeDesktopXml = QStringLiteral("freedesktop.org.xml");
@@ -301,6 +303,15 @@ void tst_QMimeDatabase::mimeTypesForFileName_data()
     QTest::newRow("non_ascii") << QString::fromUtf8("AİİA.pdf") << (QStringList() << "application/pdf");
 }
 
+static QStringList mimeTypeNames(const QList<QMimeType> &mimes)
+{
+    QStringList mimeNames;
+    mimeNames.reserve(mimes.size());
+    for (const auto &mime : mimes)
+        mimeNames.append(mime.name());
+    return mimeNames;
+}
+
 void tst_QMimeDatabase::mimeTypesForFileName()
 {
     QFETCH(QString, fileName);
@@ -313,6 +324,24 @@ void tst_QMimeDatabase::mimeTypesForFileName()
     QCOMPARE(mimeNames, expectedMimeTypes);
 }
 
+void tst_QMimeDatabase::mimeTypesForFileName_glob_deleteall()
+{
+#if !defined(USE_XDG_DATA_DIRS)
+    QSKIP("This test requires XDG_DATA_DIRS");
+#endif
+
+    QMimeDatabase mdb;
+    QList<QMimeType> mimes = mdb.mimeTypesForFileName(u"foo.webm"_s);
+
+    // "*.webm" glob pattern is deleted with "glob-deleteall"
+    QVERIFY2(mimes.isEmpty(), qPrintable(mimeTypeNames(mimes).join(u',')));
+    mimes = mdb.mimeTypesForFileName(u"foo.videowebm"_s);
+    QCOMPARE(mimes.size(), 1);
+    QCOMPARE(mimes.at(0).globPatterns(), QStringList{"*.videowebm"});
+    // Custom "*.videowebm" pattern is used instead
+    QCOMPARE(mimes.at(0).name(), u"video/webm");
+}
+
 void tst_QMimeDatabase::inheritance()
 {
     QMimeDatabase db;